EURRECA—Estimating Vitamin D Requirements for Deriving Dietary Reference Values

The time course of the EURRECA from 2008 to 2012, overlapped considerably with the timeframe of the process undertaken by the North American Institute of Medicine (IOM) to revise dietary reference intakes for vitamin D and calcium (published November 2010). Therefore the aims of the vitamin D-related activities in EURRECA were formulated to address knowledge requirements that would complement the activities undertaken by the IOM and provide additional resources for risk assessors and risk management agencies charged with the task of setting dietary reference values for vitamin D. A total of three systematic reviews were carried out. The first, which pre-dated the IOM review process, identified and evaluated existing and novel biomarkers of vitamin D status and confirmed that circulating 25-hydroxyvitamin D (25(OH)D) concentrations is a robust and reliable marker of vitamin D status. The second systematic review conducted a meta-analysis of the dose-response of serum 25(OH)D to vitamin D intake from randomized controlled trials (RCT) among adults to explore the most appropriate model of the vitamin D intake-serum 25(OH)D) relationship to estimate requirements. The third review also carried out a meta-analysis to evaluate evidence of efficacy from RCT using foods fortified with vitamin D, and found they increased circulating 25(OH)D concentrations in a dose-dependent manner but identified a need for stronger data on the efficacy of vitamin D-fortified food on deficiency prevention and potential health outcomes, including adverse effects. Finally, narrative reviews provided estimates of the prevalence of inadequate intakes of vitamin D in adults and children from international dietary surveys, as well as a compilation of research requirements for vitamin D to inform current and future assessments of vitamin D requirements.